Fast and reliable channel classification algorithms in bluetooth networks to detect and avoid 2.4 GHz interferers

ABSTRACT

Aspects of a method and system for fast and reliable channel classification in Bluetooth networks to detect and avoid channel interferers may include one or more processors that may enable performance of signal strength measurements on received Bluetooth signals at a current selected frequency. At least one data packet received via the Bluetooth signals may be processed to determine the presence of bit errors. The processor(s) may enable characterization of the Bluetooth signals at the current selected frequency based on the signal strength measurements and/or the processing of the data packets. The current selected frequency may be selected during adaptive frequency hopping based on the characterization.

CROSS-REFERENCE TO RELATED APPLICATIONS/INCORPORATION BY REFERENCE

NOT APPLICABLE.

FIELD OF THE INVENTION

Certain embodiments of the invention relate to Bluetooth wirelesscommunications. More specifically, certain embodiments of the inventionrelate to a method and system for fast and reliable channelclassification in Bluetooth networks to detect and avoid channelinterferers.

BACKGROUND OF THE INVENTION

Bluetooth is a short range wireless communications capability thatenables connection between consumer and computer equipment whileeliminating wires. Equipment that is enabled to utilize Bluetoothtechnology may be referred to as Bluetooth devices. Bluetooth deviceswithin a range of approximately 10 meters of each other may communicateutilizing a 2.4 gigahertz (GHz) frequency spectrum in the Industrial,Scientific and Medical (ISM) frequency band. The Bluetooth frequencyspectrum comprises a range of frequencies from 2.4 GHz to 2.4835 GHz.The 2.4 GHz frequency spectrum comprises a set of 79 channels, eachchannel separated by 1 megahertz (MHz). The lowest frequency channel is2.402 GHz, and the highest frequency channel is 2.48 GHz.

Examples of Bluetooth devices may comprise personal digital assistants(PDA), headsets, telephones, home audio equipment, and computers.Capabilities enabled by Bluetooth technology may comprise eliminatingcables linking computers to printers, keyboards, and mouse devices,making calls from a wireless headset connected via wireless link to awired or wireless telephone, and the playing of audio from a portableMP3 player via a home audiovisual system with no wired connectionbetween the MP3 player and the home audiovisual system.

Bluetooth is designed to enable a plurality of Bluetooth devices tooperate in a personal area network (PAN) environment. The plurality ofBluetooth devices in an environment may comprise a network known as apiconet. Within the approximately 10 meter range of Bluetooth technologya plurality of piconets may exist. Thus, Bluetooth technology may enablea plurality of piconets to coexisting within a home environment. Forexample, a first piconet may comprise computer equipment in a homeenvironment, a second piconet may comprise audiovisual equipment in ahome environment, a third piconet may comprise appliances in the homeenvironment such as air conditioners, ovens, and lighting, and so forth.

Bluetooth devices communicate by utilizing frequency hopping spreadspectrum (FHSS) techniques. FHSS enables data, represented as a sequenceof packets, to be transmitted in such manner that the portion of datacontained each packet is modulated by a frequency carrier selected froma group of available channels within the 2.4 GHz Bluetooth frequencyspectrum. The ordered sequence in which channels are selected isreferred to as a frequency hop sequence. Bluetooth devices in a piconetshare a common frequency hop sequence. A primary Bluetooth device,serving in a supervisory role in the piconet, establishes the commonfrequency hop sequence to be utilized within the piconet. AuxiliaryBluetooth devices, serving in subordinate roles in the piconet, utilizethe common frequency hope sequence established by the primary Bluetoothdevice.

For a given Bluetooth device, the integrity of data transmitted insignals may be comprised if the data is transmitted via a channel thatis current being utilized. For example, a given channel may be utilizedby another Bluetooth device. In addition, wireless local area network(WLAN) stations also use the 2.4 GHz frequency spectrum. From theperspective of a specific Bluetooth device that is currentlytransmitting data via a specific channel, other Bluetooth devices, andWLAN stations that are currently transmitting data via the same channelare referred to as “interferers”.

Further limitations and disadvantages of conventional and traditionalapproaches will become apparent to one of skill in the art, throughcomparison of such systems with some aspects of the present invention asset forth in the remainder of the present application with reference tothe drawings.

BRIEF SUMMARY OF THE INVENTION

A system and/or method is provided for fast and reliable channelclassification in Bluetooth networks to detect and avoid channelinterferers, substantially as shown in and/or described in connectionwith at least one of the figures, as set forth more completely in theclaims.

These and other advantages, aspects and novel features of the presentinvention, as well as details of an illustrated embodiment thereof, willbe more fully understood from the following description and drawings.

BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 is a block diagram of an exemplary Bluetooth piconet, which maybe utilized in connection with an embodiment of the invention.

FIG. 2 is a block diagram of an exemplary wireless communication system,which may be utilized in connection with an embodiment of the invention.

FIG. 3 is a flowchart illustrating an exemplary method for activechannel assessment, in accordance with an embodiment of the invention.

FIG. 4 is a flowchart illustrating an exemplary method for passivechannel assessment, in accordance with an embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

Certain embodiments of the invention may be found in a method and systemfor fast and reliable channel classification in Bluetooth networks todetect and avoid channel interferers. In various embodiments of theinvention, a Bluetooth device may generate a channel map by utilizing acombination of active and passive channel assessment methods. The activechannel assessment method enables classification of an RF channel thatmay not currently be in use. The passive channel assessment methodenables classification of an RF channel that is currently in use by theBluetooth device. The active channel assessment method may compriseperforming received signal strength indication (RSSI) measurements on anRF channel that may not currently be in use. Based on the RSSImeasurement, the measured RF channel may be classified as being Good orBad. If the measured RF channel is classified as being Bad, and iscurrently referenced in the channel map, the measured RF channel may beremoved from the channel map. If the measured RF channel is classifiedas being Good, and is currently not referenced in the channel map, themeasured RF channel may be added to the channel map.

The passive channel assessment method may comprise performing RSSImeasurements on an RF channel that is currently in use when there areopportunities to do so, for example during time instants when data isnot being received. In addition, packets received via the in use channelmay be evaluated to detect bit errors in the data contained within thepackets. Based on the RSSI measurement and the bit error assessments ofreceived packets, the in use RF channel may be classified as Good orBad. If the in use RF channel is classified as Bad, the channel may beremoved from the channel map. In various embodiments of the invention,“binning” and “blanking” methods may be utilized to enable removal of aplurality of RF channels from the channel map when a single RF channelis classified as being Bad.

FIG. 1 is a block diagram of an exemplary Bluetooth piconet, which maybe utilized in connection with an embodiment of the invention. Referringto FIG. 1, there is shown a piconet 100, a piconet 120, and a wirelesslocal area network (WLAN) 150. In various embodiments of the invention,the piconet 100 may comprise an adapted piconet, which is capable ofsupporting adaptive frequency hopping (AFH). The piconet 100 maycomprise a primary Bluetooth device 102, and a plurality of auxiliaryBluetooth devices 104, 106 and 108. An exemplary primary Bluetoothdevice 102 shown in FIG. 1 is a computer 102. An exemplary auxiliaryBluetooth device 104 shown in FIG. 1 is a Smartphone. An exemplaryauxiliary Bluetooth device 106 shown in FIG. 1 is a television set. Anexemplary auxiliary Bluetooth device 108 shown in FIG. 1 is a radio. Invarious embodiments of the invention, the primary Bluetooth device andone or more auxiliary Bluetooth devices may be capable of supportingAFH. The piconet 120 may comprise a plurality of Bluetooth devices 122,and 124. An exemplary Bluetooth device 122 shown in FIG. 1 is a smartphone. An exemplary Bluetooth device 124 shown in FIG. 1 is a wirelesstelephone. The WLAN 150 may comprise a plurality of WLAN stations 152and 154, which communicate according to relevant WLAN specifications,such as is set forth in IEEE 802.11, for example. An exemplary WLANstation 152 shown in FIG. 1 is an access point (AP). An exemplary WLANstation 154 shown in FIG. 1 is a computer.

In various embodiments of the invention, each of the auxiliary Bluetoothdevices 104, 106 and 108 may utilize passive channel assessment methodsto classify the RF channels utilized for communicating with the primaryBluetooth device 102. In addition, each of the auxiliary Bluetoothdevices 104, 106 and 108 may utilize active channel assessment methodsto classify RF channels, which are not currently being utilized forcommunicating with the primary Bluetooth device 102. Each of theauxiliary Bluetooth devices 104, 106 and 108 may generate a channelclassification report, which comprises classification results for eachof the RF channels assessed during active and/or passive channelassessment. Each of the auxiliary Bluetooth devices 104, 106 and 108 maycommunicate the channel classification report to the primary Bluetoothdevice 102.

Similarly, the primary Bluetooth device 102 may utilize passive channelassessment methods to classify the RF channels utilized forcommunicating with each of the auxiliary Bluetooth devices 104, 106 and108. The primary Bluetooth device 102 may also utilize active channelassessment methods to classify RF channels, which are not currentlybeing utilized for communicating with one or more of the auxiliaryBluetooth devices 104, 106 and 108. In an exemplary embodiment of theinvention, the primary Bluetooth device 102 may generate a channelclassification report based on the results of the active and passivechannel assessment methods performed by the primary Bluetooth device102. In an alternative exemplary embodiment of the invention, theprimary Bluetooth device 102 may combine the results of its active andpassive channel assessment methods with the results of the active andpassive channel assessment methods performed by one or more of theauxiliary Bluetooth devices 104, 106 and 108.

Since the ISM frequency band is unlicensed frequency spectrum, there isa possibility that Bluetooth devices 102, 104, 106 and/or 108 in thepiconet 100 may simultaneously utilize an RF channel that is also beingutilized by Bluetooth devices 122 and 124 in the piconet 120, and/or byWLAN stations 152 and 154 in the WLAN 150. From the perspective ofBluetooth devices 102, 104, 106 and/or 108, Bluetooth devices 122 and124, and/or WLAN stations 152 and 154 may be referred to as interferers.In various embodiments of the invention, RF channels, for which use byinterferers is detected, may be removed from the channel map utilized inthe piconet 100.

FIG. 2 is a block diagram of an exemplary wireless communication system,which may be utilized in connection with an embodiment of the invention.Referring to FIG. 2, there is shown a wireless communication system 200.The wireless communication system 200 may represent a Bluetooth device,and/or a WLAN station as shown in FIG. 1. The wireless communicationsystem 200 may comprise a processor 282, a memory 272, a transceiver274, an RF front end 208, and an antenna 276. The transceiver 274 maycomprise a receiver 284, and a transmitter 286.

In the context of the present application, the processor 282 may enabledigital receiver and/or transmitter functions in accordance withapplicable communications standards. In addition, the processor 282 mayenable the performance of active and/or passive channel assessmentmethods, the generation of channel classification reports, thecommunication of the generated channel classification reports from anauxiliary Bluetooth device to a primary Bluetooth device, the generationand/or modification of channel maps, and the selection of RF channelsbased on adaptive frequency hopping (AFH), for example.

The memory 270 may comprise suitable logic, circuitry and/or code thatmay enable storage and/or retrieval of data and/or code. The memory mayutilize any of a plurality of storage medium technologies, such asvolatile memory, for example random access memory (RAM), and/ornon-volatile memory, for example electrically erasable programmable readonly memory (EEPROM). In the context of the present application, thememory 270 may enable storage of code that enables performance of activeand/or passive channel assessment methods, the storage of data containedin channel classification reports, and the storage of data contained inchannel maps, for example.

The receiver 284 may perform digital receiver functions that maycomprise, but are not limited to, generation of frequency carriersignals corresponding to selected RF channels, the demodulation ofreceived RF signals by the generated frequency carrier signals, and thedetection of data. The data may be communicated to the processor 282,which may delineate packet boundaries, and compute packet error ratestatistics indicative of the presence or absence of detected bit errorsin received packets.

The transmitter 286 may perform digital transmitter functions that maycomprise, but are not limited to, generation of frequency carriersignals corresponding to selected RF channels, the modulation of data bythe generated frequency carrier signals, and the generation of produceRF signals. The data may be received from the processor 282.

The RF front end 280 may provide amplification of signals received fromthe transmitter 286 and enable transmission of the amplified RF signalvia the antenna 276. The RF front end 280 may also provide amplificationand/or filtering of signals received from the antenna 276. The filteredand/or amplified RF signal may then be communicated to the receiver 284.

In various embodiments of the invention the transceiver 274 may bereplaced by separate receiver and transmitter blocks. In addition, thewireless communication system 200 may comprise a plurality of antennas276. For example, in an exemplary embodiment of the invention, thewireless communication systems 200 may comprise one or more antennasadapted for transmitting signals, and one or more antennas adapted forreceiving signals.

FIG. 3 is a flowchart illustrating an exemplary method for activechannel assessment, in accordance with an embodiment of the invention.The active channel assessment method may be utilized at a primaryBluetooth device 102, and/or at an auxiliary Bluetooth device. ABluetooth device, which may perform an active channel assessmentprocedure, and/or a passive channel assessment procedure may be referredto as a measuring Bluetooth device. The active channel assessment methodmay be utilized to classify an RF channel, which is not currently beingutilized by the measuring Bluetooth device for transmitting and/orreceiving of data packets.

Referring to FIG. 3, step 302 indicates the beginning of a channelclassification update interval. The channel classification update maycomprise a procedure by which a channel map may be updated to reflectcurrently available RF channels. In this regard, the channel map may bereferred to as an available channel map. In an exemplary embodiment ofthe invention, a channel classification update interval may represent atime duration spanning the beginning of a current channel classificationprocedure, to the beginning of the following channel classificationprocedure. In various embodiments of the invention, the channelclassification update interval may be configurable, for example in anexemplary embodiment of the invention the channel classification updateinterval may be set to a value of 2 seconds.

In step 304, a list of currently unused RF channels may be generated.The list of unused RF channels may comprise the set of RF channels,which are not currently being utilized for transmitting data packets bythe Bluetooth device, which is performing the active channel assessmentprocedure.

In step 306, loop variables may be initialized. The variable i is anexemplary loop variable, which may be utilized to count the number ofRSSI measurements that are performed for each unused RF channel duringthe current channel classification update interval. The variableRSSI_(Total) is an exemplary loop variable, which may be utilized tomaintain a total value among the RSSI measurements that are performedfor each unused RF channel during the current channel classificationupdate interval.

In step 308, an RSSI value, RSSI_(i), may be measured for each unused RFchannel in the list of unused RF channels that was generated in step304. In step 310, the value RSSI_(i) determined in step 308 may be addedto the current value of RSSI_(Total) for each unused RF channel. In step312, an average RSSI value, RSSI_(Avg), may be computed for each unusedRF channel. The value RSSI_(Avg) represents an average RSSI value foreach of the i number of RSSI measurements performed during the currentchannel classification update interval. The value RSSI_(Avg) may becomputed for each unused RF channel.

In step 314, a determination may be made as to whether to continuemaking subsequent RSSI measurements for each unused RF channel in thecurrent channel classification update interval. The time duration forwhich RSSI measurements may be performed within a current channelclassification update interval may be configurable. In variousembodiments of the invention the RSSI measurement time duration may beless than or equal to the channel classification update interval. In anexemplary embodiment of the invention, the time duration for which RSSImeasurements may be performed, or “dwell time”, may comprise about ½ ofa time slot within a 1 MHz Bluetooth channel. If, in step 314, it isdetermined that RSSI measurements are to continue, in step 316, thevalue for the variable i may be incremented by 1. Step 308 may followand the procedure of RSSI_(i) measurement, RSSI_(Total) calculation, andRSSI_(Avg) calculation may continue.

If, in step 314, it may be determined that RSSI measurements are not tocontinue in the current channel classification update interval, step 318may begin the process of classifying each RF channel in the list ofunused RF channels. In step 320, the current value RSSI_(Avg) may becompared to a threshold RSSI value, RSSI_(Thresh), for each unused RFchannel. In various embodiments of the invention, the RSSI thresholdvalue may be configurable and may represent a quantity measure in unitsof decibels (dB). An average RSSI value for an unused RF channel, whichis greater than the threshold RSSI value, may indicate that aninterferer is currently utilizing the RF channel. When this is the case,step 322 may indicate that the RF channel is classified as being “Bad”.An average RSSI value for an unused RF channel, which may not be greaterthan the threshold RSSI value, may indicate that the RF channel may beavailable to the measuring Bluetooth device for subsequent transmissionof data packets. When this is the case, step 324 may indicate that theRF channel is classified as being “Good”. Step 302 may follow step 322or step 324 where the process may pause while awaiting the beginning ofthe next channel classification update interval.

After classifying each of the unused RF channels as being Good or Bad,one or more of the auxiliary Bluetooth devices may generate an availablechannel map based on the classifications of step 322 and/or 324. Theavailable channel map may be communicated to the primary Bluetoothdevice 102 by the one or more auxiliary Bluetooth devices.

FIG. 4 is a flowchart illustrating an exemplary method for passivechannel assessment, in accordance with an embodiment of the invention.The passive channel assessment method may be utilized at a primaryBluetooth device 102, and/or at an auxiliary Bluetooth device. Thepassive channel assessment method may be utilized to classify an RFchannel, which is currently being utilized by the measuring Bluetoothdevice for transmitting and/or receiving of data packets.

Referring to FIG. 4, step 402 indicates the beginning of a channelclassification update interval. The channel classification update maycomprise a procedure by which a channel map may be updated to reflect adetermination of whether a currently used RF channel is to remain in theavailable channel map. In various embodiments of the invention, thechannel classification update interval may be configurable, for examplein an exemplary embodiment of the invention the channel classificationupdate interval may be set to a value of 10 seconds.

In step 404, loop variables may be initialized. The variable N_(Good) isan exemplary loop variable, which may be utilized to count the number ofinstances, during the current channel classification update interval,for which a currently used RF channel passed “Good” channel criteria. Invarious embodiments of the invention, examples of Good channel criteriamay comprise comparing a measured RSSI value to a threshold RSSI value,RSSI_(Thresh), and detection of 0 bit errors in data packets receivedvia the currently used RF channel. The variable N_(Bad) is an exemplaryloop variable, which may be utilized to count the number of instances,during the current channel classification update interval, for which acurrently used RF channel did not pass as least one of the “Good”channel criterion.

In step 406, an RSSI value, RSSI_(R) _(—) _(Ch), may be measured foreach currently used RF channel at the measuring Bluetooth device. TheRSSI value for the currently used RF channel may be measured during oneor more timeslot time intervals for which the measuring Bluetooth deviceis not currently transmitting data packets. While the measuringBluetooth device may not be currently transmitting data packets, thedevice would have not yet relinquished the RF channel. Consequently, theRF channel may still be considered to be “in-use”. In step 408, themeasured value RSSI_(R) _(—) _(Ch) may be compared to the threshold RSSIvalue, RSSI_(Thresh). In various embodiments of the invention, the RSSIthreshold value may be configurable as described for FIG. 3 above. Ameasured RSSI value for a currently used RF channel, which may not begreater than the threshold RSSI value, may indicate that no interferer,which is also currently utilizing the RF channel, has been detected.When this is the case, in step 412, the variable N_(Good) may beincremented. In an exemplary embodiment of the invention, the variableN_(Good) may be incremented by 1 as shown in FIG. 4.

A measured RSSI value for a currently used RF channel, which is greaterthan the threshold RSSI value, may indicate detection of an interferer,which is also currently utilizing the RF channel. When this is the case,in step 410, a data packet received via the used RF channel may beinspected to determine the presence of one or more detected bit errorsin the received data packet. Various methods may be utilized fordetection of bit errors, for example forward error correcting (FEC)codes comprising inner codes, such as binary convolutional coding (BCC)may be utilized, and/or outer codes, such as cyclical redundancychecking (CRC) or Reed-Solomon coding, may be utilized. If no bit errorsare detected in step 410, step 412 may follow step 410. If bit errorsare detected in step 410, in step 414, the variable N_(Bad) may beincremented. In an exemplary embodiment of the invention, the variableN_(Bad) may be incremented by 1 as shown in FIG. 4.

In step 416, a determination is made as to whether to continue makingsubsequent RSSI measurements for each currently used RF channel in thecurrent channel classification update interval. The time duration forwhich RSSI measurements may be performed within a current channelclassification update interval may be configurable. In variousembodiments of the invention the RSSI measurement time duration may beless than or equal to the channel classification update interval. If, instep 416, it is determined that RSSI measurements are to continue, instep 406 may follow and the procedure of RSSI_(R) _(—) _(Ch)measurement, RSSI_(Thresh) comparison, and possible bit error detectionin received data packets may continue.

If, in step 416, it is determined that RSSI measurements are not tocontinue in the current channel classification update interval, in step418, the ratio N_(Good)/N_(Bad) may be compared to a threshold ratio,R_(Thresh), for each currently used RF channel. In various embodimentsof the invention, the ratio N_(Good)/N_(Bad) may provide an indicationof the rate at which each currently used RF channel passed Good channelcriteria during the current channel classification update interval. Whenthe ratio N_(Good)/N_(Bad) exceeds the threshold ratio, it may indicatethat the currently used RF channel is not subjected to significantinterference from interferers. When this is the case, step 420 mayindicate that the currently used RF channel is classified as Good.

In instance when the ratio N_(Good)/N_(Bad) does not exceed thethreshold ratio, it may indicate that the currently used RF channel issubjected to significant interference from interferers. The interferencemay result in unacceptably high measured RSSI values and in unacceptablyhigh rates of detected bit errors in received packets, or packet errorrate (PER). When this is the case, step 422 may indicate that thecurrently used RF channel is classified as being Bad. Step 402 mayfollow either step 422 or step 424 where the process may pause whileawaiting the beginning of the next channel classification updateinterval.

After classifying each of the currently used RF channel as being Good orBad, one or more of the auxiliary Bluetooth devices may generate anavailable channel map based on the classifications of step 422 and/orstep 424, and/or of step 322 and/or 324 (FIG. 3). The available channelmap may be communicated to the primary Bluetooth device 102 by the oneor more auxiliary Bluetooth devices.

In some instance, the nature of the traffic carried via a currently usedRF channel may limit the number of opportunities for performing passivechannel assessment. In this case, the active channel assessment method,as described in FIG. 3, may also be performed for the currently used RFchannel. In this regard, the currently used RF channel may be classifiedbased on the results of active channel assessment and/or passive channelassessment methods. In an exemplary embodiment of the invention, acurrently used RF channel may be classified as being Bad if either theactive channel assessment method or the passive channel assessmentmethod classifies the currently used RF channel as being Bad.

In various embodiments of the invention, the primary Bluetooth device102 may classify individual RF channels as being Good or Bad based onits own channel assessment, and/or based on channel assessmentscommunicated by one or more auxiliary Bluetooth devices. In an exemplaryembodiment of the invention, the primary Bluetooth device 102 maycompute a weighted channel assessment as set forth in the followingequation:

$\begin{matrix}{Q_{j} = \frac{P_{j} + {\sum\limits_{i = 1}^{N_{A}}\left\lbrack {{\alpha \cdot P_{j}} + {\left( {1 - \alpha} \right) \cdot A_{ij}}} \right\rbrack}}{1 + N_{A}}} & \lbrack 1\rbrack\end{matrix}$where Q_(j) represents a weighted classification of RF channel j, P_(j)represents the classification of RF channel j performed by the primaryBluetooth device utilizing active and/or passive channel assessmentprocedures, A_(ij) represents the classification of RF channel jperformed by the i^(th) auxiliary Bluetooth device, N_(A) represents thenumber of auxiliary Bluetooth devices in the piconet 100, and arepresents a weighting factor. The weighting factor provides a measureof the influence of the value P_(j) in computing the weightedclassification Q_(j). For example, when α=1, Q_(j)=P_(j), and when α=0,the primary Bluetooth device and each of the auxiliary Bluetooth devicescontribute with equal weight in the computation of the weightedclassification value Q_(j). In an exemplary embodiment of the invention,for each of the classification variables P_(j), A_(ij), and Q_(j), avalue of 0 may indicate a Bad classification, while a value 1 mayindicate a Good classification. In an exemplary embodiment of theinvention, numerical rounding may be utilized such that the value Q_(j)is rounded to the nearest integer value. For example, for valuesQ_(j)<0.5 computed according to equation [1], the rounded value may beQ=0, while for Q_(j)≧0.5, the rounded value may be Q_(j)=1.

In various embodiments of the invention, the primary Bluetooth device102 may compute values Q_(j) for each of the RF channels utilized inBluetooth communications, as set forth in equation [1], and an updatedavailable channel map generated based on these computations. The updatedavailable channel map may be subsequently utilized for AFH duringBluetooth communications within a piconet 100.

Various embodiments of the invention may also utilize methods referredto for purposes of the present application as “binning”, and “blanking”.The binning method may comprise a procedure by which a plurality ofassociated RF channels may be classified as being Bad if a separate RFchannel is classified as being Bad. In an exemplary embodiment of theinvention, if a given RF channel is classified as being Bad, thepreceding RF channel and the succeeding RF channel may also beclassified as being Bad. In this case, the bin size would be 3 MHz,given 1 MHz RF channels.

In various embodiments of the invention, the bin size, or the number ofassociated RF channels, which are classified as being Bad based on aseparate RF channel being classified as being Bad may be configurable.In addition, the relationship between the separate RF channel beingclassified as Bad, and the one or more associated RF channels beingclassified as Bad as a result may be configurable (for example, the setof RF channels classified as being Bad may not comprise a contiguousblock of frequencies).

The blanking method may also comprise a procedure by which a pluralityof associated RF channels may be classified as being Bad if a separateRF channel is classified as being Bad. In this case, however, therelationship between the separate RF channel and associated RF channelsmay be based on a WLAN channel. In an exemplary WLAN, a single WLANchannel may comprise 21 MHz, wherein the frequency band occupancy of theWLAN channel may comprise a range of +/−10 MHz around a centerfrequency. In an exemplary embodiment of the invention, when 5individual Bluetooth RF channels are classified as being Bad, which fallwithin the frequency range of one of the commonly used WLAN channelsCH1, CH6, or CH11, a set of Bluetooth RF channels, which fall within thefrequency range of the corresponding WLAN channel, may be classified asbeing Bad. When 10 individual Bluetooth RF channels are classified asbeing Bad, which fall within the frequency range of one of the otherWLAN channels, a set of Bluetooth RF channels, which fall within thefrequency range of the corresponding WLAN channel may be classified asbeing Bad.

In various embodiments of the invention, the threshold for number ofBluetooth RF channels classified as being Bad within the frequency rangeof a single WLAN channel that may result in blanking, or classificationof the set of Bluetooth RF channels as being Bad, which fall within thefrequency range of the single WLAN channel, may be configurable. Invarious embodiments of the invention, blanking may not be limited to thefrequency range of WLAN channels but may be applied in variousforeseeable wireless communications settings. The invention may not belimited to Bluetooth devices, but may be practiced within a wide rangeof foreseeable wireless communications setting utilizing suitablewireless communication devices. In various embodiments of the invention,an available channel map generated based on active and/or passivechannel assessment methods by the primary and/or auxiliary Bluetoothdevices may be modified based on binning and/or blanking as set forthabove.

Aspects of a method and system for fast and reliable channelclassification in Bluetooth networks to detect and avoid channelinterferers may comprise one or more processors 282 that may enableperformance of signal strength measurements on received Bluetoothsignals at a current selected frequency. At least one data packetreceived via the Bluetooth signals may be processed to determine thepresence of bit errors. The processors 282 may enable characterizationof the Bluetooth signals at the current selected frequency based on thesignal strength measurements and/or the processing of the data packets.The current selected frequency may be selected during adaptive frequencyhopping at a subsequent time based on the characterization.

The signal strength measurements and/or processing of the data packetsmay be performed within a current channel classification updateinterval. The processor 282 may enable a signal clear count to bemaintained to count the number of instances during the current channelclassification update interval during which the signal strengthmeasurement is less than or equal to a threshold value. The data packetprocessing may occur when the signal strength measurement is greaterthan the threshold value. The processor 282 may enable a signalinterference count to be maintained to count the number of instancesduring which a bit error is detected in the processed data packets foreach instance when the signal strength measurement is greater than thethreshold value.

The processor 282 may enable the characterization to be performed bycomparing a ratio of the signal clear count, and the signal interferencecount, to a threshold ratio. The characterization may determine whetherthe received Bluetooth signal is Good or Bad based on the comparison.The processor 282 may enable selection of the current selected frequencyat the subsequent time when the received Bluetooth signal ischaracterized as being Good.

The processor 282 may enable removal of the current selected frequencyfrom an available channel map when the receive Bluetooth signal ischaracterized as being Bad. The processor 282 may enable generation ofan updated available channel map based on the available channel map, andat least one received auxiliary channel map. The auxiliary channel mapsmay be received by a primary Bluetooth device 102, for one or moreauxiliary Bluetooth devices 104, 106 and/or 108 within a piconet 100.The processor 282 may enable selection of a weighting factor, α, forgeneration of the updated available channel map. The processor 282 mayenable removal of one or more frequencies other than the currentselected frequency from the available channel map.

The processor 282 may enable signal strength measurements performed atfrequencies other than the current selected frequency. The processor 282may enable performance of the signal strength measurements within acurrent channel classification update interval. An average value for thesignal strength measurements may be computed during the current channelclassification update interval. The average value may be compared to athreshold value. The processor 282 may enable removal of the other thancurrent selected frequency from the available channel map based on thecomparison.

Accordingly, the present invention may be realized in hardware,software, or a combination of hardware and software. The presentinvention may be realized in a centralized fashion in at least onecomputer system, or in a distributed fashion where different elementsare spread across several interconnected computer systems. Any kind ofcomputer system or other apparatus adapted for carrying out the methodsdescribed herein is suited. A typical combination of hardware andsoftware may be a general-purpose computer system with a computerprogram that, when being loaded and executed, controls the computersystem such that it carries out the methods described herein.

The present invention may also be embedded in a computer programproduct, which comprises all the features enabling the implementation ofthe methods described herein, and which when loaded in a computer systemis able to carry out these methods. Computer program in the presentcontext means any expression, in any language, code or notation, of aset of instructions intended to cause a system having an informationprocessing capability to perform a particular function either directlyor after either or both of the following: a) conversion to anotherlanguage, code or notation; b) reproduction in a different materialform.

While the present invention has been described with reference to certainembodiments, it will be understood by those skilled in the art thatvarious changes may be made and equivalents may be substituted withoutdeparting from the scope of the present invention. In addition, manymodifications may be made to adapt a particular situation or material tothe teachings of the present invention without departing from its scope.Therefore, it is intended that the present invention not be limited tothe particular embodiment disclosed, but that the present invention willinclude all embodiments falling within the scope of the appended claims.

1. A method for frequency selection in a wireless communication system,the method comprising: in a wireless device: performing at least onesignal strength measurement on a corresponding at least one Bluetoothsignal received at a current selected frequency; processing at least onedata packet received via said received at least one Bluetooth signal todetermine the presence of bit errors; characterizing said received atleast one Bluetooth signal received at said current selected frequencybased on said at least one signal strength measurement and/or saidprocessing said at least one data packet; classifying said currentselected frequency based on said characterization of said received atleast one Bluetooth signal received at said current selected frequency,and based on an assessment of said current selected frequency receivedfrom one or more additional wireless devices; and selecting, duringadaptive frequency hopping (AFH), said current selected frequency basedon said classification.
 2. The method according to claim 1, comprisingperforming said at least one signal strength measurement and saidprocessing said at least one data packet within a current channelclassification update interval.
 3. The method according to claim 2,comprising maintaining a signal clear count of a number of instancesduring said current channel classification update interval, wherein avalue of said at least one signal strength measurement is less than orequal to a threshold value.
 4. The method according to claim 3,comprising performing said processing of said at least one data packetfor each of said value of said at least one signal strength measurementthat is greater than said threshold value.
 5. The method according toclaim 4, comprising maintaining a signal interference count of a numberof instances, wherein at least one bit error is detected in saidprocessed at least one data packet for each of said value of said atleast one signal strength measurement that is greater than saidthreshold value.
 6. The method according to claim 5, comprisingperforming said characterizing by comparing a ratio of said signal clearcount and said signal interference count to a threshold ratio.
 7. Themethod according to claim 6, wherein said characterizing determineswhether said received at least one Bluetooth signal is Good or Bad basedon said comparing.
 8. The method according to claim 7, comprisingselecting said current selected frequency when said received at leastone Bluetooth signal is Good.
 9. The method according to claim 7,comprising removing said current selected frequency from an availablechannel map when said received at least one Bluetooth signal is Bad. 10.The method according to claim 9, comprising generating an updatedavailable channel map based on said available channel map and at leastone received auxiliary available channel map.
 11. The method accordingto claim 10, comprising selecting a weighting factor for said generatingof said updated available channel map.
 12. The method according to claim9, comprising removing at least one frequency, other than said currentselected frequency, from said available channel map.
 13. The methodaccording to claim 1, comprising performing at least one signal strengthmeasurement at a frequency other than said current selected frequency.14. The method according to claim 13, comprising performing said atleast one signal strength measurement within a current channelclassification update interval.
 15. The method according to claim 14,comprising computing an average value for said at least one signalstrength measurement during said current channel classification updateinterval.
 16. The method according to claim 15, comprising comparingsaid average value to a threshold value.
 17. The method according toclaim 16, comprising removing said frequency, other than said currentselected frequency, from an available channel map based on saidcomparing.
 18. A system for frequency selection in a wirelesscommunication system, the system comprising: at least one processor tobe utilized in a wireless device, said at least one processor enablesperformance of at least one signal strength measurement on acorresponding at least one Bluetooth signal received at a currentselected frequency; said at least one processor enables processing of atleast one data packet received via said received at least one Bluetoothsignal to determine the presence of bit errors; said at least oneprocessor enables characterization of said received at least oneBluetooth signal received at said current selected frequency based onsaid at least one signal strength measurement and/or said processing ofsaid at least one data packet; said at least one processor enablesclassification of said current selected frequency based on saidcharacterization of said received at least one Bluetooth signal receivedat said current selected frequency, and based on an assessment of saidcurrent selected frequency received from one or more additional wirelessdevices; and said at least one processor enables selection, duringadaptive frequency hopping (AFH), of said current selected frequencybased on said classification.
 19. The system according to claim 18,wherein said at least one processor enables performance of said at leastone signal strength measurement and said processing of said at least onedata packet within a current channel classification update interval. 20.The system according to claim 19, wherein said at least one processorenables maintenance of a signal clear count of a number of instancesduring said current channel classification update interval, wherein avalue of said at least one signal strength measurement is less than orequal to a threshold value.
 21. The system according to claim 20,wherein said at least one processor enables performance of saidprocessing of said at least one data packet for each of said value ofsaid at least one signal strength measurement that is greater than saidthreshold value.
 22. The system according to claim 21, wherein said atleast one processor enables maintenance of a signal interference countof a number of instances, wherein at least one bit error is detected insaid processed at least one data packet for each of said value of saidat least one signal strength measurement that is greater than saidthreshold value.
 23. The system according to claim 22, wherein said atleast one processor enables performance of said characterization bycomparing a ratio of said signal clear count and said signalinterference count to a threshold ratio.
 24. The system according toclaim 23, wherein said characterization determines whether said receivedat least one Bluetooth signal is Good or Bad based on said comparison.25. The system according to claim 24, wherein said at least oneprocessor enables selection of said current selected frequency when saidreceived at least one Bluetooth signal is Good.
 26. The system accordingto claim 24, wherein said at least one processor enables removal of saidcurrent selected frequency from an available channel map when saidreceived at least one Bluetooth signal is Bad.
 27. The system accordingto claim 26, wherein said at least one processor enables generation ofan updated available channel map based on said available channel map andat least one received auxiliary available channel map.
 28. The systemaccording to claim 27, wherein said at least one processor enablesselection of a weighting factor for said generation of said updatedavailable channel map.
 29. The system according to claim 26, whereinsaid at least one processor enables removal of at least one frequency,other than said current selected frequency, from said available channelmap.
 30. The system according to claim 18, wherein said at least oneprocessor enables performance of at least one signal strengthmeasurement at a frequency other than said current selected frequency.31. The system according to claim 30, wherein said at least oneprocessor enables performance of said at least one signal strengthmeasurement within a current channel classification update interval. 32.The system according to claim 31, wherein said at least one processorenables computation of an average value for said at least one signalstrength measurement during said current channel classification updateinterval.
 33. The system according to claim 32, wherein said at leastone processor enables comparison of said average value to a thresholdvalue.
 34. The system according to claim 33, wherein said at least oneprocessor enables removal of said frequency, other than said currentselected frequency, from an available channel map based on saidcomparison.